But police cite witness accounts of excessive speed, the driver's own admission that she was looking down at her cell phone before the crash and a bottle of open vodka in the back compartment.

Troopers found the three-quarters full bottle of Burnett's Pomegranate vodka in the rear compartment and said it was cold to the touch. They do not believe it factored into the crash, however, and a breathalyzer test of the 16-year-old driver showed no alcohol in her system.

Danielle Michaels, the driver, told police she was driving and had been on a cell phone with her mother "when she looked down at her phone to turn it off," a trooper wrote in the report.

"She looked up and saw a vehicle right in front of her that she believed she was going to hit," the trooper wrote. "She swerved her vehicle to avoid hitting the vehicle in front of hers, losing control and leaving the roadway."

Michaels and front seat passenger Hannah DeVecht, 17, were wearing seat belts and were the least seriously injured when the SUV rolled over after hitting a cable barrier. It flipped onto the shoulder of the westbound lanes after hitting another cable barrier on that side of the freeway.

Back seat passengers Brittney Olds, 16, Emily Bogner, 16 and Madison Case, 17, all were thrown out of the vehicle and seriously injured. Olds is at Mary Free Bed hospital, still recovering.

The teens were in a caravan of vehicles, including buses, headed to a Grand Haven girls semi-final basketball game in East Lansing.

The cell phone appears to be only one of the possible distractions in the vehicle. In an interview with another driver on the freeway who witnessed the crash, that person told investigators there seemed to be a lot of commotion in the SUV in the moments before it went off the road.

"The young girls in the back seat were hanging out the windows, yelling at kids on the buses in the right lane and moving around in the vehicle from side to side," the trooper wrote.

Another witness told police the CRV appeared to be speeding before the crash and passed her vehicle going an estimated 90 mph.

Phone records obtained by police confirmed that Michaels received an incoming phone call at 11:25 a.m.

"This information would verify what she stated at the hospital, that she had just hung up the phone before the crash occurred," the trooper wrote.

State Police Lt. Chris McIntire said he did not believe that investigators came to a final resolution on how the alcohol got into the vehicle.

Michaels told troopers that "'she knew it was in the back seat but she didn't know who bought it. She also mentioned it might have been left in the vehicle from a previous day."

McIntire said the police report will be forwarded to the Kent County prosecutor's office for review.

He did not know whether Michaels or the other teens would be charged with anything.

Possible charges are minor-in-possession and, for the driver, having open intoxicants in a vehicle. The driver also could conceivably be charged with a relatively new statute "moving violation causing serious injury."